Blood glucose tracking system

ABSTRACT

A blood glucose tracking system and method measures emitted microwave energy transmitted to and accepted by blood vessels in a desired target area of a patient in order to determine, in real time and in vivo, appropriate blood glucose levels. A measurement unit comprises a transmitter operatively connected to an antenna to deliver energy towards appropriate subcutaneous blood vessels. The measurement unit determines an accepted energy power value in the blood vessels associated with the desired target area. This measurement energy power value is compared with a calibration value, and the difference is used to determine a resultant blood glucose value. The determined blood glucose value may further be acclimatized using additional sensed values compensating for biological and ambient factors relevant to the patient. The final determined blood glucose value can be displayed for reading and/or transmitted and stored for recording for further reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/118,827, filed on Aug. 31, 2018, which claims the benefit of U.S.Provisional Patent Application No. 62/646,510, filed Mar. 22, 2018, eachof which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention generally relates to non-invasive, in vivo bloodglucose measurement systems, and more particularly to a personalizedsubcutaneous blood glucose measurement and tracking system forinstantaneous real-time readings of blood glucose values.

BACKGROUND

For decades, attempts have been made to develop a system for “real-time”direct reading, non-invasive measurement of glucose levels in thebloodstream. To date, these efforts have been unsuccessful primarily dueto the inherent nature of glucose itself, which readily dissolves inblood, as well as the containment of the bloodstream in the human body,making a direct, non-invasive measurement of glucose residing in thebloodstream extremely difficult.

Historically, optical methods have been favored in attempts to measureblood glucose levels utilizing visible light, infra-red light, or byattempting to detect polarization changes caused by varying glucoselevels in the blood. These efforts have repeatedly proven fruitless, aswere other attempts at direct, non-invasive measurement of blood glucoselevels.

Presently available continuous blood glucose monitoring systems, inreality, actually measure interstitial fluid glucose levels rather thandirectly measuring blood glucose levels. As a result, such “bloodglucose” systems or meters do not provide “real time” blood glucosereadings. In addition, such systems inherently suffer from a substantialtime lag—generally about 20 minutes with the correlation of interstitialfluid measurements relative to blood glucose readings.

Although generally recognized that blood glucose levels have been ableto be measured fairly accurately via microwave means in vitro undercontrolled laboratory conditions, prior art measuring equipment haslacked the ability to make these measurements in vivo. While clinicallyuseful measurements may be possible in such fixed laboratory conditions,a mechanism and embodiment that allows for actual non-invasive bloodglucose readings “in the field” has heretofore not existed, to saynothing about the automatic calibration mechanisms that are needed todevelop these simple laboratory measuring devices into a system that issuitable for everyday use with actual living beings who exhibitindividual variations and characteristics from one another.

In view of the foregoing, there is a need for an actual (direct reading)blood glucose measurement system that is non-invasive and can be used invivo without exhibiting the inherent measurement variation and time lagto determine blood glucose measurements generally associated with priorart “blood glucose” meters that are actually “interstitial fluid”measuring devices. Accordingly, it is a general object of the presentinvention to provide a novel blood glucose tracking system that providesa new, optimized and efficient approach to blood glucose measurement,tracking and monitoring, that is non-invasive, directly measures bloodglucose, and can be done in vivo without measurement variation and timelag.

SUMMARY

The present invention, directed to a blood glucose tracking system andmethod, works differently than prior art “blood glucose” meters andprior attempts at non-invasive measurement devices. Instead of trying toduplicate the specialized and optimized equipment needed to measure theglucose level of a solution in a controlled laboratory setting, thepresent invention achieves an accurate calculation of said glucose leveldirectly from the bloodstream by measuring how much overall emittedmicrowave energy is transmitted to and subsequently accepted by bloodvessels in a defined and fixed target area, and then comparing thisinstantaneous measurement value against a prior calibration value. Thedifference between the instantaneous power reading measurement and theprior calibration power reading measurement is analyzed and calculatedto determine a resultant blood glucose value, which may further beacclimatized through additional sensed values that compensate forvarying biological or ambient factors or changes relative to theindividual patient. Still further, the determined blood glucose valuecan be displayed for reading and/or transmitted and stored for recordingfor future reference.

Unlike all presently available continuous “blood-glucose” meters (which,as noted above, actually measure interstitial fluid rather than bloodglucose directly), the blood glucose tracking system in accordance withthe present invention actually reads the instantaneous glucoseconcentration in a bloodstream. Additionally, unlike prior art metersthat read interstitial fluid, the system reads and provides ablood-glucose value in real time without any time lag betweenmeasurement and actual blood-glucose readings. Still further, such realtime measurements allow the blood glucose levels to be measured andmonitored in vivo utilizing a compact measurement unit that canpreferably be worn by the individual for in vivo use.

The system and method of the present invention is inherently differentto other prior art systems and methods mainly in that the presentinvention relates to a direct absorptive measuring system, and uniquelydoes not depend on measuring transmitted energy that has beentransmitted from a transmitting element through layers of skin and/orother body parts to a receiving element.

In accordance with preferred embodiments of the present invention, thesystem and method of blood glucose measurement utilizes a shortduty-cycle, high impulse power/very-low average-power microwave energysource, preferably transmitting radio frequency energy. Bloodcomposition averages about 92% water overall. It is a known fact thatwater-containing glucose absorbs microwave energy to an extent greaterthan water without glucose. By exploiting this phenomenon, there existsa practical pathway to finally being able to non-invasively detect andmeasure the instantaneous in-vivo level of glucose in the bloodstream.In accordance with preferred embodiments, the microwave energy from theenergy source is fed into an antenna assembly designed to focus andtransmit this energy toward appropriate subcutaneous blood vessels,namely, those blood vessels that are closest to the surface of the skin.In further preferred embodiments, the energy source and antenna assemblyare provided in a housing mountable to the patient's body proximatesubcutaneous blood vessels to be measured in a desired target area, morepreferably mountable to the patient's arm, and even more preferablymountable to the patient's wrist, for example, as part of a bracelet orwatch.

A unique and important part of the system and method of blood glucosemeasurement in accordance with the present invention is the use of anindividually tailored Radio frequency (RF) mask for each target patientand that individual's desired target area. Such an RF mask permits thetransmitted microwave energy to reach only an exactly outlined targetarea of interest, such as, specific segments of near-surface bloodvessels. Moreover, the microwave energy may be further contained, shapedand exclusively directed to a location and depth confirming to aspecifically defined area that contains said “near surface” bloodvessels by optimizing the antenna radiation lobe pattern(s), transmittedfrequencies chosen, and power levels used. The same RF mask that limitsthe area(s) to which RF energy is directed and allowed to be transmittedalso inherently limits the measurements of energy that otherwise wouldbe absorbed outside of the desired target area, thus greatly increasingthe accuracy of readings using the system and method of the presentinvention.

In an aspect of the present invention, the microwave energy iscontained, shaped, and exclusively allowed to be directed towards adesired target area to a depth in a confirming specific area thatcontains subcutaneous blood vessels. The antenna assembly is preferablylocated adjacent to the desired target area. In embodiments, the antennaradiation lobe patterns, transmitted frequencies, and power levels canbe varied with respect to specific patients and target areas on saidpatients.

In preferred embodiments of the present invention, the power levelsneeded to reach the targeted subcutaneous blood vessels are achieved byusing pulsed-type radio wave emissions, similar to those used by radartransmitters.

In accordance with embodiments of the present invention, with eachcalibration, a known glucose value and its corresponding delivered powervalue could be placed into a memory buffer. As the test subject'sglucose level changes, this would result in the average power levelaccepted by the bloodstream through the system to either rise or fall invalue relative to a power value associated with the last calibrationvalue. With each subsequent periodic microwave emission, the measurementunit would record all new data, and calculate blood glucose values basedon an extrapolation of the change in the delivered/accepted power levelbetween the instantaneous power level and previous calibration values.

Objects, features and advantages of the present invention will becomeapparent in light of the description of embodiments and featuresthereof, as enhanced by the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic embodiment of a blood glucose trackingsystem in accordance with the present invention for non-invasive in vivoblood glucose measurement.

FIG. 2 illustrates another embodiment of the blood glucose trackingsystem in accordance with the present invention, whereby the system isembodied in a wristwatch.

FIG. 3 illustrates yet another embodiment of the blood glucose trackingsystem in accordance with the present invention, whereby an auxiliaryhousing, including an antenna, is connected to a watch or bracelethousing a wireless transmitter, ideally worn on a wrist.

FIG. 4 illustrates a schematic embodiment of a blood glucose trackingsystem whereby data related to determined blood glucose levels isprovided to a computer, display, or memory buffer, as desired.

FIG. 5 illustrates another schematic embodiment of a blood glucosetracking system involving two transmitters.

FIG. 6 illustrates a mask used on a patient to limit the area(s) towhich energy transmitted from a measurement device in accordance withthe present invention is allowed to be transmitted to.

FIG. 7 provides a flow chart illustrating a test sequence in accordancewith preferred embodiments of the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, a schematic embodiment of a blood glucose trackingsystem for non-invasive in vivo blood glucose measurement in accordancewith the present invention is illustrated. The system generallycomprises a measurement unit 10 having a microwave energy source (suchas a transmitter 12) operatively connected to an antenna assembly,generally comprising an antenna 14, via coaxial cable or a waveguide,generally represented as reference numeral 16. The transmitter 12 andthe antenna 14 may be disposed within a common antenna housing 18, asillustrated, or disposed in separate units, provided that they areoperatively connected with one another. The antenna assembly alsopreferably comprises a controller/processor 24, which is used to measurethe amount of power/energy delivered through the antenna 14. Thetransmitter 12 may also be in operative communication with thecontroller 24.

The transmitter 12 comprises a very-low average-power microwave energysource and short duty-cycle, high-impulse power, preferably transmittingradio frequency energy, and more preferably emitting pulsed-type radiowave emissions similar to those used by radar transmitters. Thetransmitter 12 feeds into the antenna 14 for focusing and transmittingmicrowave energy towards appropriate subcutaneous blood vessels 20located at a desired target area 50 on the patient. In use, themeasurement device 10 measures the microwave energy absorbed in thenear-by blood vessels 20 to aid in determining the blood glucose levelsin the target area 50. More particularly, the controller 24 measures thepower delivered to the blood vessels 20 by determining how much energygenerated by the transmitter 12 is outputted by the antenna 14. Asillustrated in FIG. 1, the antenna housing 18 is placed on or near thepatient's skin S proximate to subcutaneous blood vessels 20 formeasurement, such as on the patient's wrist.

Referring to the schematic illustration of FIG. 7, the system achievesan accurate calculation of the patient's blood glucose levels in adefined and fixed target area 50 by measuring how much overall emittedmicrowave energy is transmitted to and accepted by subcutaneous, or“near surface”, blood vessels 20 in the target area 50, preferably byabsorption therein. Instantaneous, real-time measurement values, takendirectly from the bloodstream, can be compared with a pre-determinedcalibration value. The difference, or “delta” value, between themeasurement value and the calibration value can provide, via analysisand calculation, a resultant blood glucose value. In preferredembodiments, an algorithm correlating power energy values with bloodglucose values is used to determine the resultant blood glucose value.Such an algorithm is preferably stored in the controller 24. Thecalibration value can be stored in a memory buffer 22, provided as partof the controller 24.

The desired subcutaneous blood vessels 20 for accurate measurement inaccordance with the present invention are typically found near thewrists of individuals, though the system of the present invention canalso be used with other parts of the body without departing from thespirit and principles of the present invention. Accordingly, the antenna14 is preferably located adjacent to a desired target area, preferablyby placing the antenna housing 18 on the skin surface S proximate to thedesired target area 50. A unique and critically important part of thesystem of the present invention is the use of individually-tailored RFmasks 52, generally illustrated in FIG. 6, for each target patient anddesired target location 50 that permits the microwave energy deliveredby the antenna 14 to only reach an exact outlined target area(s) ofinterest, such as specific segments of near-surface blood vessels 20. Byfurther optimizing the antenna radiation lobe pattern(s), transmittedfrequencies chosen, and power levels used, the microwave energy isfurther contained, shaped, and exclusively directed to a depth in aconfirming specific area that contains said “near surface” blood vessels20. As the skin S in these areas is exceedingly thin, not only is iteasy to actually see the blood vessel locations, but it should be alsonoted that these areas have almost nothing in the pathway between theantenna 14 and the targeted blood vessels 20 to unduly attenuate orinterfere with the transmission path.

The system and method of the present invention is inherently differentto other prior art systems and methods in that the present invention isa direct absorptive measuring system, and uniquely does not depend onmeasuring transmitted energy that has been transmitted from atransmitting element through layers of skin and/or other body parts to areceiving element.

In use, an RF mask 52 is created for an individual patient, and thenlaid on and temporarily adhered to the patient's skin S over the desiredtarget area 50, as generally illustrated in FIG. 6, and then used withthe measurement unit 10 described herein for blood glucose measurementand tracking. The same RF mask 52 that limits the area(s) to which theRF energy is allowed to be transmitted also inherently limits themeasurements of energy that otherwise would be absorbed outside of thetarget area 50, thus greatly increasing the accuracy of readings.Preferred methods for creating individualized RF masks 52 are describedin more detail below.

As noted, the power levels needed to reach the targeted subcutaneousblood vessels 20 are achieved by using pulsed-type radio wave emissions,similar to those used by radar transmitters. Although the “peak” powerlevels may be relatively high (in order to penetrate the skin to thedepth necessary), the duty cycle of these emissions is quite low, whichresults in the “average” power level being quite low. This makes such awireless transmitter 12 not only very energy efficient, but also suchemissions do not result in any perceptible temperature rise by theindividual wearing such a system, as opposed to continuous waveemissions that are typically used in laboratory equipment.

The extrapolation process of determining the amount of energy absorbed(e.g., the power reading measurement) may utilize one or more of thefollowing processes, either alone or in combination:

In a first approach, the antenna assembly measures one of deliveredforward emitted peak power level and/or average power levels at aspecific radio frequency over a specific time frame. More specifically,as the microwave pulses are emitted from the antenna 14, their peaktransmitted power level and/or average power level are measured by thecontroller 24. Then, the “delta” value for the measured transmittedenergy power level in comparison to a calibration value recorded at thetime of the last calibration reading/measurement is determined. Thesystem identifies, via an algorithm, a new calculated blood glucosereading that corresponds to the measured energy power levels. Moreparticularly, the algorithm correlates specific blood glucose levelswith energy absorption data. The calculated/determined blood glucosereading can be provided to a display and/or memory buffer, as desired.

In a second approach, instead of reading the forward power levelactually delivered and/or accepted by the target blood vessels 20, thesystem measures the reflected energy power levels in the blood vessels20 of the desired target area 50 to determine a “delta” value incomparison with a calibration value. In this case, lower reflected powerreadings would indicate a greater energy acceptance in the target area50, which would, in turn, indicate and track with higher glucose levels.The higher the levels of glucose in the blood, the greater willingnessfor the blood to absorb energy, which would reduce the reflected power.As with the first approach, the calculated “delta” value, the systemidentifies, via the algorithm, a new calculated blood glucose reading.The calculated/determined blood glucose reading can be provided to adisplay and/or memory buffer, as desired.

In a third approach, the system measures Standing Wave Ratio (SWR)readings from the transmitter 12 at a specific radio frequency and fromsuch a measurement, calculates a “delta” value in relation tocalibration readings. In this case, SWR readings generally track bloodglucose levels, wherein the SWR readings rise with lower levels of bloodglucose, and decrease with higher levels. The calculated “delta” valueis again used, via the algorithm, to determine the appropriate bloodglucose reading, when can be provided to a display and/or memory buffer,as desired.

The various processes listed above have all of their power measurementstaking place at a fixed frequency. In accordance with a fourth approach,the transmitter 12 is commanded to sequentially vary its transmissionfrequency in a pre-determined fashion, frequency stepping in a repeatinglow-to-high, or high-to-low fashion, within a predetermined frequencyrange. The amount of energy acceptance from each of the individuallytransmitted radio frequencies utilized would be measured for either peakor average power delivered, and then compared to the other frequenciesin the same measurement cycle. The shift in the absorption rate betweenfrequencies would track changing glucose levels, and would beextrapolated to a blood glucose value using one or more extrapolationmethods. One embodiment that can be used with this method woulddynamically analyze the location of the frequency that accepted maximumenergy absorption, which would then become the “center” or “index”frequency. This “index” frequency would be compared to the lastcalibration “index” frequency, to create an offset value. This offsetvalue would be applied to a scaling algorithm to determine a calculatedblood glucose value, which can then be provided to a display and/ormemory buffer, as desired.

A similar approach may utilize the frequency hopping method of thefourth approach, but rather than solving for and analyzing a “center” or“index” frequency, this approach would instead analyze the energychanges in all of the various transmitted frequencies to indicate the“spread” or bandwidth of those frequencies that showed microwave energyabsorptive activity above a predetermined threshold, and then comparethe instantaneous spread of those frequencies above the threshold withthe spread of the readings obtained at the last calibration. Analgorithm would analyze the increase or decrease of the spread to comeup with a difference value, and this value would be applied to analgorithm to calculate a blood glucose reading, which can then beprovided to a display and/or memory buffer, as desired.

With each subsequent periodic microwave emission, the measurement unit10 would record all new data, and determine a blood glucose value basedon an extrapolation of the change in the delivered/accepted power levelbetween the instantaneous power level and the previous calibrationvalue. As an example, if the calibration entry resulted in a directblood glucose reading of 100 and the blood at that glucose level hadaccepted 100 milliwatts of power from the transmitter 12 (assuming thesystem were using a 1:1 algorithm), a new test reading showing a 10%rise in the power delivered to the target area 50, or 110 milliwatts,would calculate to a blood glucose level of 110 mg/dl.

In addition to the base transmitter 12 and power sensing via the antennaassembly, the blood glucose tracking system and method in accordancewith the present invention, can utilize additional optional compensationmethods to enhance the accuracy of the blood glucose readings. Amongthese methods are the following:

-   -   (A) A pulse rate sensor incorporated to compensate for change in        the rate of blood flow through the blood vessels 20. A faster or        slower blood flow would alter the rate of energy acceptance, and        could detrimentally skew the calculated results. To compensate        for this, a pulse rate sensor would be optionally incorporated        to allow a dynamic compensation for this variable.    -   (B) A skin temperature sensor in close proximity to the desired        target area 50 allows for temperature compensation to be applied        to optimize for changing blood vessel diameters (e.g.,        vasodilation; vasoconstriction) due to body core temperature        variations.    -   (C) By measuring the skin galvanic response, this measurement,        preferably along with the skin temperature monitor, can        determine the level of sweat production in the area of the        measurement unit 10, which could skew the microwave absorption        rate. As a result, the system can compensate for sweat        production based on measurement of skin galvanic data.    -   (D) Although blood generally averages 92% water, there are times        when the hydration levels of the patient may vary widely. A        periodic microwave energy measurement at a frequency more        resonant for water (as opposed to one more resonant to glucose)        could be used to continuously calibrate the measurement unit 10        to account for varying hydration levels of the patient. Either        dual band microwave transmitters, or a wide-band single band        transmitter which is capable of operating at wide frequency        variances would allow one frequency or transmitter to be        dedicated to monitoring water levels, while the other frequency        or transmitter would be optimized for glucose detection, in the        manner described above.

Additional measurement and display means can be provided with themeasurement unit 10. For example, a display screen 26 can be provided onthe antenna housing 18, as illustrated in FIGS. 2 and 4. Additionally,the measurement unit 10 can be part of or take the form of a bracelet orwatch 28 worn around the wrist, or comprise a localized unit attached tothe skin S, for example, by an adhesive. Additional transmitter means 30can further be included, as schematically illustrated in FIG. 5, totransmit data from the measurement unit 10 to another unit 32, such as acomputer, tablet or smart phone, for display and/or recording of bloodglucose measurements taken by the measurement unit 10. For example, ameasurement unit 10 in the form of a bracelet or watch 28 could storemeasured data, and then sync with a computer 32 for additional storage,monitoring and analysis of a patient's blood glucose measurements.

The blood glucose tracking system in accordance with the presentinvention may be a discrete “stand-alone” system, such as describedabove and illustrated in FIG. 1, or may be incorporated into anunrelated item worn on the wrist (such as a watch or jewelry) to takeadvantage of the near-surface blood vessels 20 of the wrist in anon-apparent fashion. In the instance of a watch 28, which would containthe transmitter 12 and its associated control components, a small fixedor flexible section of miniature waveguide 34 could be attached to thebody of the watch 28, while the other end would connect to a detachableauxiliary “side car” antenna housing 36 placed over the desired targetarea for measurement. Thus, such an auxiliary antenna housing 36,including the antenna 14 and its associated control components 24, couldbe attached to the watch 28 for measurements, and detached when notneeded. When the housings 18 and 36 are attached, the antenna 14 can beconnected to the transmitter 12 via a waveguide or coaxial cable 34running through the band of the watch 28. In the case of a watch or“smart watch” as illustrated in FIG. 2, in which a blood glucosetracking system in accordance with the present system may beincorporated as an integral part thereof, the existing digital readout26 of the watch 28 could be used to display instantaneous blood glucosereadings.

Numerous other creative physical embodiments may be utilized withoutdeparting from the spirit and principles of the present invention, forexample, by incorporating a metal shield to limit the antenna energytowards an adjacent desired target area 50, or batteries to power the RFtransmitter 12 or other equipment located within the watchband segments.

The system may also incorporate a separate data transmitter 30 (which,as noted above, is in addition to the sampling transmitter 12) to relaythe raw or calculated data output to a separate display 32 or storagedevice 38, such as a computer, tablet or smart phone, or to a devicesuch as an insulin pump 40. Depending on the manufacturer or model ofsuch devices, the data output would be sent in the appropriateproprietary format for, as noted, display and/or storage.

The system and method in accordance with the present invention deriveinstantaneous blood glucose readings by comparing differences between a“control” reading, in which the blood glucose value is known, with aninstantaneous reading, in which the blood glucose value is not known andneeds to be determined. The “control” reading can be a calibrationvalue, which can be adjusted after each such calibration measurementusing the system (e.g., a new control measurement value becomes thecalibration value for the next measurement). In order to accuratelyextrapolate the instantaneous glucose readings with the level ofmicrowave energy accepted, a periodic calibration performed by anappropriate measurement method, such as by utilizing a traditional“finger stick” blood glucose testing method, or other means ofaccurately determining actual blood glucose levels. This data wouldprovide the measurement unit 10 with a standard reference measurement,which would then be used to compare subsequent readings for a specificbody and body target location (such as certain blood vessels in a wrist)in an individual to provide and track subsequent blood glucose readings.

In order to create unique individualized RF antenna masks 52, such asillustrated in FIG. 6, two preferred methods of mask creation may beutilized. The first, a “manual” method, utilizes a thin piece of Mylaror other flexible transparent material that is temporarily wrappedaround an individual's wrist or other location associated with a desiredtarget area 50, and held in place. A marking pen is used to outline theexact target area 50 for the antenna 14, along the width of thesubject's arm or other body part, to provide subsequent positioningreference guidance. After removal, the flexible sheet is laid over ablank antenna mask and the overlay is used to guide the cutting of themask opening area. Once the RF mask 52 is created, it can be laid on andtemporarily adhered to the patient's skin S at the desired target area50, and used with the measurement unit 10 described herein formeasurement and tracking of blood glucose levels.

The second preferred RF mask creation method is an “automatic” method bywhich the desired target area 50 is photographed or scanned in thevisible and/or thermal infrared spectrum. The thermal data can furtherbe used to establish the best sensing areas. A physical measurement isalso made of the general area surrounding the desired target area 50.The resulting photo data is fed into a laser cutting machine or CNCmachine that scales the cutting information based upon the measurements,and then automatically selects and outlines the unmasked area tocorrespond to the optimized target are criteria. The cutting machine(s)can directly create a mask opening on a non-RF transmissive materialsheet. This automatic selection process may be as a result of either thegathered visible information or the gathered IR thermal information, orboth.

The foregoing description of embodiments of the present invention hasbeen presented for the purpose of illustration and description. It isnot intended to be exhaustive or to limit the invention to the formdisclosed. Obvious modifications and variations are possible in light ofthe above disclosure. The embodiments described were chosen to bestillustrate the principles of the invention and practical applicationsthereof to enable one of ordinary skill in the art to utilize theinvention in various embodiments and with various modifications assuited to the particular use contemplated.

What is claimed is:
 1. A blood glucose measurement device comprising: anantenna housing having an antenna assembly disposed therein, saidantenna housing being adapted for placement on or near a patient's skinproximate to a desired target area comprising blood vessels to bemeasured, and said antenna assembly comprising an antenna; and atransmitter operatively connected to the antenna for transmittingmicrowave energy into the blood vessels of the target area via theantenna, wherein the antenna assembly measures microwave energy absorbedin the blood vessels in the target area and determines an absorbedmicrowave energy measurement value that can be correlated with thepatient's blood glucose level.
 2. The blood glucose measurement deviceaccording to claim 1, further comprising a controller for comparing theabsorbed microwave energy measurement value with a calibration value toidentify a difference between said values, and thereafter determining ablood glucose value based on said difference.
 3. The blood glucosemeasurement device according to claim 1, wherein the blood vessels inthe desired target area are subcutaneous blood vessels.
 4. The bloodglucose measurement device according to claim 1, wherein the measurementdevice is adapted to be placed on the patient's arm proximate thedesired target area.
 5. The blood glucose measurement device accordingto claim 4, wherein the measurement device is adapted to be placed onthe patient's wrist.
 6. The blood glucose measurement device accordingto claim 4, further comprising a strap to which the antenna housing isattached, said strap being adapted to be wrapped around the patient'sarm.
 7. The blood glucose measurement device according to claim 1,further comprising a visual display for displaying measurement datacorresponding to the absorbed microwave energy measurement value.
 8. Theblood glucose measurement device according to claim 1, furthercomprising a second transmitter for transmitting measurement data to anexternal device for at least one of display and storage of themeasurement data.
 9. The blood glucose measurement device according toclaim 1, wherein the microwave energy is in the form of microwavepulses.
 10. The blood glucose measurement device according to claim 1,wherein the antenna assembly measures actual energy power levelsdelivered to the blood vessels in the target area.
 11. The blood glucosemeasurement device according to claim 1, wherein the antenna assemblymeasures reflected energy power levels delivered to the blood vessels inthe target area.
 12. The blood glucose measurement device according toclaim 1, wherein the antenna assembly measures a standing wave ratioreading representative of energy absorption in the blood vessels in thetarget area.